1. Field of the Invention
This invention relates to a waterproof seal for use in a waterproof connector.
2. Description of the Related Art
A waterproof connector has a construction, for example, as shown in FIG. 6. A metal terminal 3 is inserted into a cavity 2 in a connector housing 1 and is retained by a lance 4 against withdrawal. A waterproof seal 6 is fitted on a wire 5 connected to the metal terminal 3. This conventional waterproof seal 6 is of a generally cylindrical shape and has opposite end surfaces that are annular and flat. The wire 5 is passed through a bore of the cylindrical seal 6, and an outer peripheral surface of the seal 6 is held in pressure-contact with an inner peripheral surface of the cavity 2.
It is a common practice to pass the wire 5 through the waterproof seal 6 of this type by the use of an automatic machine in assembling the connector. Waterproof seals 6 are supplied to a wire insertion machine by a parts feeder. In the parts feeder, a number of waterproof seals 6 are charged, for example, into a stock bowl, and the seals 6 then are supplied therefrom one by one in a row to the wire insertion machine by vibration.
The waterproof seal of this type is often made of oil-containing rubber, comprising silicone rubber impregnated with oil, so that the material of the seal is more water repellant, thereby enhancing a waterproof performance of the connector. However, the oil exudes to the surface of the waterproof seal, and therefore, the waterproof seals charged into the stock bowl have often stuck to one another because of a surface tension of the oil. More specifically, since the conventional waterproof seal has the opposite flat end surfaces of a relatively large size, adjacent waterproof seals 6 have become stuck at their ends to one another as shown in FIG. 7 and FIG. 8, which has made it difficult to arrange the waterproof seals in order in the parts feeder, thus causing troubles in the manufacture of the connectors.